A variety of health risks have been associated with terrorist attacks in the United States and elsewhere. Past terrorist attacks have included the use of weapons and explosives as well as the use of poisons, for example, Ricin and infectious agents, for example, Anthrax. There is a growing concern that terrorists may make use in the future of other infectious agents, and in particular, smallpox.
Smallpox was essentially eradicated by 1977 through a comprehensive global immunization program. Therefore, smallpox vaccinations were globally terminated in 1977. As a result, people born after 1977 are unlikely to have been vaccinated against smallpox, and those vaccinated in 1977 or prior are unlikely to still be protected against the smallpox virus. Though smallpox was eradicated from the worldwide human population, smallpox virus samples still exist in various laboratories worldwide.
Following the attack on the World Trade Center and the Anthrax attack on the federal building in Washington D.C. in 2001, President Bush initiated a national smallpox vaccination program, requesting near-term immunization of military personnel deployed to certain regions. Furthermore, if a smallpox attack occurs, the Center for Disease Control (CDC) suggests rapid vaccination of a variety of other people, including those directly exposed, contacts of those directly exposed, health care workers responsible for the care of those with confirmed infection, laboratory workers who handle smallpox specimens, allied personnel handling laundry, waste, and dead bodies associated with smallpox victims, law enforcement personnel, and EMTs.
A smallpox vaccination is administered using a bifurcated needle to administer the vaccination intradermally, unlike the more typical type of vaccination administered using a hypodermic needle in an intramuscular injection. With the intradermal technique, it is important to administer the vaccination at the correct depth into the skin of a patient, and also to be familiar with characteristics of scarification that occur days after the vaccination to determine if the vaccination was properly administered and to determine if the patient had the proper reaction. Because health care workers have not used intradermal techniques since 1977 to administer smallpox vaccinations, it is possible that, if the need arises to rapidly perform smallpox vaccinations, the health care workers will not be able to properly administer the smallpox vaccinations and will not be able to properly interpret the resulting scarification.
Unlike conventional vaccines, which are made from inactive virus particles, the smallpox vaccine uses live vacinia virus (similar to cowpox) to induce immunity to variola virus (smallpox). Therefore, when administering a smallpox vaccination, it is desirable to reduce or eliminate contamination of other people with the vacinia virus. Methods practiced decades ago to administer smallpox vaccinations were suitable for the elimination of contamination to the other people. It is possible that health care workers have not been trained in the techniques necessary to eliminate the contamination to other people by the vacinia virus.